Machinery packing



MACHINERY PACKING Filed April 21, 1957 M/LINVENTOR. BY M ATTORNEY.

Patented Dec. 12, 1939 pNiTEo STATES eATENT OFFICE v .MAGHINERY PACKING Norman Bruce'Miller, New York, N. Y. Application April 21, 1937, Serial N0.,138,084

2 Claims. (01. 288-12) each other provide a continuous metal contact,

throughout the body of strands which is desirable as providing a reliable and suitable support for the packing against its bearing surfaces.

15 To hold the strips together, however, they have been enclosed in a coveringsuch as woven cotton fabric. The introduction of this fabric into the packing strip introduces unreliability thereuntoas regards the proper support and adjusting 20, of the bearing surface of the packing upon the moving member. This is because the introduction of the fabric introduces a different and unreliable element into the packing inasmuch as the continuity of metal contact and support throughout 25 the packing is destroyed and the reliability of the adjustment bearing and wearing qualities of the packing are impaired. According to the present invention the advantages of the metallic strand packing as referred to are secured and at the "30, same time the disadvantages referred to are avoided by applying suitable metal to the exterior of the fabric covering causing the metal to impregnate the fabric to the interior thereof and in contact with the metal strands within. This 35 provides a continuous metal contact and support from the outer surface of the packing strip which bears against the moving part, entirely across the packing, and this is true at the moment the packing is first placed in position and thereafter 40 while the packing is in use.' The reliability of the packing as to both adjustment, bearing surface 50 comes in contact with the metal of the strands,

the continuous metalliccontact from the outer surface of the strip inwardly, with the advantages as indicated, being thus obtained.

It has been found that with a machinery pack- 5 ing strip having metal strands extending alongside each other and longitudinally of the strip, that. such strands better cooperate to'give the desired results in the packing if they are made channeled or concave in cross section.

-It is therefore a further object of the inven '5 tion to make the packing strands of channeled form or concave in cross section.

It has further been found that better cooperation of the strands in the packing to produce the desired results is attained by making the packing strands with rough or serrated edges.

It is a further object of the invention to provide a packing having strands with serrated or rough edges.

It has further been found that the strands of 1 the packing have an improved cooperation if the strands are made channeled or concave in cross section and also with serrated or rough edges.

It is therefore a further object of the invention to provide a packing comprising strands whichare channeled or concave in cross section, and also have serrated or rough edges.

Other and ancillary objects of the invention will appear hereinafter.

In the accompanying drawing which illustrates the invention Fig. 1 is an axial section through a stufiing box showing the manner .of the improved packing thereto;

Fig. 2 is a fragmentary, perspective view of one of the groups of metallic strands employed in the packing;

Fig. 3 is a fragmentary, perspective view showing the assembly of several groups of the metallic strands assembled together; Fig. 4 is an enlarged cross sectional view of a packing strip embodying the invention; and

Fig. 5 is a fragmentary, perspective view, on

an. enlarged scale, of a metal strand which enters into the construction of the packing. 40

Referring to the drawing, the rotating shaft passing through the wall 2 is packed against leakage along the shaft by means of the strips of packing .3 contained in the stuffing box l wherein the packing is secured and compressed by means of the gland 5 which may be of any suitable type. It will be understood that the stufiing box here shown is intended merely as an illustration of one way of utilizing the present packing and is not a part of the present inven- 450 tion. It will beseen that the packingin the stufiing box comprises three strips of packing, but obviously one or more strips might be used according to the desires of the operator or the necessity of the character of use. Each strip of packing has the cross sectional appearance substantially as Fig. 4.

The strip of packing as seen in cross section in Fig. 4 comprises four groups 6, 1, 8 and 9 of strands l0, each of which groups comprises a number of strands of suitable metal such as lead, or some composition thereof, which extend alongside each other and longitudinally of the strip. Each of the strands may be of any appropriate size but are preferably formed from thin sheet metal foil so as to be readily flexible, and each of the strands is of the shape as shown in Fig. 5 from which it will be seen that the strip is concave in cross section or longitudinally channeled at H. The edges [2 of each of the strands are serrated or roughened by reason of being torn (rather than cut) from a sheet of metal. This strip is as formed in the machine as described in my application Serial No. 133,083 filed herewith. This channeled strip with the serrated edges engages and interlocks with the other similar strips with which it is assembled, so as to produce an advantageous interaction between them.

The strands ll! of each group are twisted together as shown in Fig. 2, the twisting being in the direction of the arrow of Fig. 2. The strands are not, however, tightly twisted together, the twisting movement being stopped while the group is yet soft and its surface quite irregular and lined with deep interstices.

There is then applied to the surface of the twisted group a coating of suitable lubricant such as flake graphite, powdered soap stone or other appropriate material.

The plurality (in this instance shown as four) of groups of strands which have been thus formed, all of the groups having been twisted in the same direction, are laid together side-by-side parallel with each other and then the groups are twisted together so that collectively they present an appearance approximately as illustrated in Fig. 3. In twisting together these groups care is taken that the twisting movement is in a direction opposite to the twisting movement which was applied to the original strands in the individual groups, that is, whereas the direction of twist of the strands in a group as seen in Fig. 2 is counterclockwise, the direction of twist of the groups together as seen in Fig. 3 is clockwise. This reversal of twisting movement is of material importance in that co-incident with the twisting together of the groups there will occur also a certain amount of untwisting of strands in the individual groups. The strands which occur at the outer surface of the groups will be most strongly affected in this regard since their movement will not be opposed by abutting portions of adjacent groups. The strands occurring at or near the surface of the respective groups where said surfaces abut adjacent groups will be affected to some extent, however, in degree according to their tightness of contact with ad-- jacent groups, and this untwisting and consequent loosening of strands of the respective groups, throughout the circumference of the groups, but particularly in the portions of the groups abutting adjacent groups will cause a loosening of the strands whereby the migration of lubrication to the various desired parts of the packing will be facilitated.

Owing to the fact that the central strands of the respective groups have relatively slight twisting or untwisting movement at any time, such central strands will-not materially loosen and hence little or none of the lubricant will find its way to the centers of the respective strand groups. The metallic strands comprising these centers will, in this way, be maintained relatively free of lubricant and hence be relatively stiff longitudinally, the degree of stifiness diminishing upwardly away from such centers as the supply of lubricant increases.

After the assembly and twisting together of the strand groups as described, external pressure is applied against the assembly so as to form the assembled groups into rectangular cross section.

Either before or after pressing the assembled strand groups into rectangular cross section, as shown in Fig. 4, a jacket M, which may be of textile cotton fabric, is placed about the entire periphery of the packing to hold the parts together, the packing thus constructed consists of a number of groups of strands, each group (Fig.

2) comprising a multitude of strands of suitable metal twisted in one direction, the strands being channeled and with rough edges so as to more thoroughly and efficiently cooperate with each other, and the assembled groups consisting of any desired number of groups, are twisted together in a reverse direction, the direction of twisting of the individual groups being indicated by the arrow in Fig. 2 and of the assembled groups by the arrow in Fig. 3.

It will be seen that in the foregoing structure, although the metal strands and groups of strands are in contact from one side of the packing strip to the other, the inter-position of the textile jacket between the shaft and the metal strands prevents a solid metal contact from the shaft throughout the packing when the packing is first inserted in position, and as the cotton jacket wears away, the packing may be thrown out of adjustment or rendered unreliable even though eventually the metal-to-metal contact between the packing and the shaft is established. To remedy this the textile fabric jacket I4 is coated with a suitable metal I3 which impregnates the fabric to the interior thereof and comes in contact with the metal packing strands within. There will thus be formed by the packing from the very moment of its insertion into place, a continuous metallic contact and support from the moving shaft to the packing and entirely across the same. This will at all times provide a reliable and desirable bearing upon the shaft and the packing will not be liable to get out of adjustment.

The metal with which the textile jacket may be impregnated may be powdered or flaked aluminum, lead or other suitable metal and may be applied to the textile covered packing strip by drawing such strip through a bath of molten wax in which the powdered metal is held in suspension or in any other suitable way.

It will be noted that the pressure applied to the packing to form strand groups into a cross section as shown in Fig. 4 will result in the individual strand groups assuming a substantially triangular shape approximately as illustrated, r

whereby the groups are brought into close cooperative relation and function efiiciently with relation to each other.

While the invention has been illustrated in what is considered its best application it may have other embodiments without departing from its spirit and is not therefore limited to the structure shown in the drawing.

What I claim is:

1. A joint packing for stufiing boxes and the.

like, comprising: a multiplicity of soft metallic strands twisted together in rope-like assembly, each of said individual strand elements consist ing initially of a long straight ribbon of soft metallic foil having irregularly serrate-side edges providing, in the twisted assembly, a-myriad of minute intersticial cavities imparting a material degree of compressibility thereto and capable of retaining a quantity of lubricating material,

therein.

2. A joint packing for stuffing boxes and the like, comprising: a multiplicity of soft metallic strands twisted together in rope-like assembly, each of said individual strand elements consistsaid coated assembly and impregnated with said metallic particles.

NORMAN BRUCE MILLER. 

